Conventional touch input modes of touch panels comprise of resistive mode, capacitive mode, optical mode, electromagnetic induction mode, and acoustic wave sensing mode, etc. For the resistive mode and capacitive mode, a user touches the surface of a panel by a finger or a stylus, causing a change of voltage and current inside touch location of the panel, and then the touch location on surface of the panel can be detected so to achieve the purpose of a touch input.
In order to detect a location on a touch panel touched by a user with a finger or a stylus, those skilled in the art have developed various capacitive touch sensing technologies. For example, structure of a grid capacitive touch circuit pattern comprises two groups of capacitive sensing layers which are spaced by an intermediate insulation layer so as to form capacitance effect. Each capacitive sensing layer comprises conductive elements which are arranged substantially parallel to each other. The two capacitive sensing layers are substantially perpendicular to each other; each conductive element comprising a series of diamond-shaped electrode blocks. The conductive element is made of a transparent conductive material (such as ITO), and the electrode blocks are connected by narrow conductive wires. Conductive elements on each capacitive sensing layer are electrically connected to a surrounding circuit. A control circuit provides signals to two groups of conductive elements respectively, via the surrounding circuits and can receive touch signals generated by electrode blocks when a surface is touched so as to determine the touch location on each layer.
Moreover, the method of manufacturing a conventional capacitive touch circuit pattern structure includes forming a plurality of electrode blocks of a first group of capacitive sensing layer through the first processing. A surrounding circuit is formed through a second process such that the surrounding circuit is connected to the electrode blocks of the first group of capacitive sensing layer, to form a whole insulation layer through a third process. A plurality of electrode blocks of a second group of capacitive sensing layer are formed through a fourth process and another surrounding circuit is formed through a fifth process. Finally the surrounding circuit is connected to the electrode blocks of the second group of the capacitive sensing layer. The shortcoming in this procedure is that for making the electrode blocks of the two groups of the capacitive sensing layers, the insulation layer and the two groups of surrounding circuits must be formed through the above disclosed five processing steps, which makes the overall process very complex. Conductive wires used for connecting the electrode blocks are made of ITO, which further makes it difficult to effectively reduce the impedance between the electrode blocks and the surrounding circuits.
Thus, there exists a need to improve sensitivity of signal transmission between the electrode blocks and the surrounding circuits.